UNW_SET_CACHING_POLICY(3) Programming Library UNW_SET_CACHING_POLICY(3)NAMEunw_set_caching_policy-- set unwind caching policy
SYNOPSIS
#include <libunwind.h>
int unw_set_caching_policy(unw_addr_space_t as, unw_caching_policy_t
policy);
DESCRIPTION
The unw_set_caching_policy() routine sets the caching policy of address
space as to the policy specified by argument policy. The policy argu‐
ment can take one of three possible values:
UNW_CACHE_NONE
Turns off caching completely. This also implicitly flushes the
contents of all caches as if unw_flush_cache() had been called.
UNW_CACHE_GLOBAL
Enables caching using a global cache that is shared by all
threads. If global caching is unavailable or unsupported, libun‐
wind may fall back on using a per-thread cache, as if
UNW_CACHE_PER_THREAD had been specified.
UNW_CACHE_PER_THREAD
Enables caching using thread-local caches. If a thread-local
caching are unavailable or unsupported, libunwind may fall back
on using a global cache, as if UNW_CACHE_GLOBAL had been speci‐
fied.
If caching is enabled, an application must be prepared to make appro‐
priate calls to unw_flush_cache() whenever the target changes in a way
that could affect the validity of cached information. For example,
after unloading (removing) a shared library, unw_flush_cache() would
have to be called (at least) for the address-range that was covered by
the shared library.
For address spaces created via unw_create_addr_space(3), caching is
turned off by default. For the local address space
unw_local_addr_space, caching is turned on by default.
RETURN VALUE
On successful completion, unw_set_caching_policy() returns 0. Other‐
wise the negative value of one of the error-codes below is returned.
THREAD AND SIGNAL SAFETYunw_set_caching_policy() is thread-safe but not safe to use from a sig‐
nal handler.
ERRORS
UNW_ENOMEM
The desired caching policy could not be established because the
application is out of memory.
SEE ALSOlibunwind(3), unw_create_addr_space(3), unw_flush_cache(3)AUTHOR
David Mosberger-Tang
Hewlett-Packard Labs
Palo-Alto, CA 94304
Email: davidm@hpl.hp.com
WWW: http://www.hpl.hp.com/research/linux/libunwind/.
Programming Library 05 August 2004 UNW_SET_CACHING_POLICY(3)
